Steel structural members or studs in the form of c-beams and box 2.times.4's have been used for a number of years in construction work as framing for interior walls and for exterior walls which support, for example, plaster board and exterior sheathing. Such steel studs when used as structural members for exterior walls have a primary drawback in that they readily conduct exterior heat into the air-conditioned building in the summer and do the reverse in winter when the heat loss in cold weather can be so serious that the walls are discolored, called "shadowing", as moisture, including greasy dirt, is deposited on the colder parts of the wall in direct contact with the steel beams supporting the wall.
How serious is this heat loss, or gain, may be seen by considering that a small house of approximately 900 square feet and having dimensions of about 32'.times.28' provided with studs 24" on center would have approximately 60 beams or studs about its perimeter. If each stud has dimensions of a 2".times.4", with the 2" sides facing outside and inside there would be a total of steel exposed to the exterior siding equivalent to an area 8' high by 10' wide surface. This is a very considerable area (over 8%) radiating cold from the exterior wall through the interior wall into the house or, in summer, radiating heat into the house.